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PubMedDate not supplied

[Life support limitation at three pediatric intensive care units in southern Brazil].

OBJECTIVES: To describe causes of death and factors involved in the decision-making process related to life support limitation at three university-affiliated pediatric intensive care units in the south of Brazil. METHODS: A retrospective study was conducted, based on a review of the medical records of all deaths occurring during 2002 at three pediatric intensive care units in Porto Alegre. Three previously trained pediatric fellows from each service performed the study. Data were assessed relating to general case characteristics, causes of death (failed cardiopulmonary resuscitation, brain death, do-not-resuscitate orders, withholding or withdrawing life-sustaining treatment -- the last three modes were classified as the life support limitation group), length of stay in hospital, end-of-life plans and the participation of patients families and Ethics Committees. The Student t test, Mann Whitney, chi-square, odds ratio and multivariate analyses were used for comparisons. RESULTS: Close to 53.3% of fatal cases had received full cardiopulmonary resuscitation. The incidence of life support limitation was 36%, with statistical differences (p = 0.014) between the three hospitals (25 versus 54.3 and 45.5%, respectively). The most frequent form of life support limitation was a do-not-resuscitate order (70%). Life support limitation was associated with the presence of chronic disease (odds ratio = 8.2; 95%CI 3.2-21.3) and length stay in the pediatric intensive care unit (odds ratio = 4.4; 95%CI 1.6-11.8). The rate of involvement of families and Ethics Committees in the decision-making process was lesser than 10%. CONCLUSIONS: Cardiopulmonary resuscitation is offered more frequently than is observed in northern countries. In contrast, life support limitation is offered through do-not-resuscitate orders. These findings and the low participation of the families in the decision-making process reflect the difficulties to be overcome by those professionals who are responsible for handling critically ill children in southern Brazil.

Brazil↗
PubMedDate not supplied

[Genetic mechanisms of realization of the law of limiting factor in Saccharomyces cerevisiae].

The law of limiting factor establishes the dependence organism functioning on the environmental conditions. The molecular basis of this adaptation determined with differentional gene's activity. The expression of more than 6000 genes in response to the deficiency in nitrogen, carbon or phosphorus in growth medium has been studied in yeast Saccharomyces cerevisiae. The model of integral yeast cell response on limiting factor was suggested on the basis of this data and the data concerning mechanisms of metabolic pathways regulation. According to this model, phosphoprotein kinase (Tor1p, Tor2p, Snf1p or Pho85p) that regulates corresponding metabolic pathway receives a signal about the limiting factor and become dominated kinase. Dominated kinase regulates activators and repressors proteins of its own metabolic pathway but it is also able to affect the activity of transcription regulators of other metabolic pathways. Proteins could be activators of one set of metabolic pathways and in the same time serve as repressors of others. That allows the regulation of cell metabolism according to the limiting factor. Dominated kinases can be involved in phosphorylation of DNA polymerases and affect the level of spontaneous mutations. Mutations that increase that viability of cells on the background of limiting factor are selected. Thus the relationship between inheritable and non-inheritable variability is not occasional and take place on the genetic level and the limiting factor is the reason for modification and inheritable variabilities.

Adaptation, Physiological↗
PubMed2005

Simultaneous anaerobic-aerobic biodegradation of halogenated phenolic compound under oxygen-limited conditions.

The successful application of co-immobilized aerobic-anaerobic biomass under limited aeration in wastewater treatment systems would eliminate the problems associated with the intermediates mono-chlorophenol (MCP) and di-chlorophenol(DCP) accumulations. With low initial pentachlorophenol (PCP) concentration, all PCP could be completely removed under oxygen-limited strict anaerobic conditions, and the removal efficiencies with different initial headspace oxygen percentage (IHOP) were not obviously different from each other. While at high initial PCP concentration, under strictly anaerobic conditions PCP and their intermediates were clearly higher than that under other conditions, and produced obvious accumulation, the highest PCP reduction was achieved by the system receiving 30 IHOP, oxygen-limited system also exhibited lower residual TOC concentration and lower concentration of metabolic intermediates MCP and DCP. These results suggested that under strictly anaerobic condition the reductive dechlorination of low chlorinated compounds became rate limiting in the reductive dechlorination pathway, less chlorinated compounds be more amenable to aerobic degradation, and the aerobes of outer layers could function under limited oxygen. The co-immobilized aerobic-anaerobic biomass for methanogenesis under limited-aeration for chlorophenol degradation might be an attractive and efficient alternative for the sequential anaerobic/aerobic system to achieve mineralization of a broad range of recalcitrance highly chlorinated organics and low final TOC concentrations.

Anaerobiosis↗
PubMed2006

Adaptation of the WHO guideline for residual DNA in parenteral vaccines produced on continuous cell lines to a limit for oral vaccines.

Although there is a WHO guidance for a limit on residual DNA for parenterally administered vaccines produced on continuous cell lines, there is no corresponding guidance for oral vaccines. To help determine an oral limit, we performed a study of Vero cell DNA uptake in rats, in which the relative uptake and persistence of Vero cell DNA administered orally was compared to its uptake when delivered intramuscularly (IM). The results of this study allowed the generation of an empirically derived IM versus oral factor (10(6)) representing the relative inefficiency of DNA uptake by oral administration. This factor was then applied to the WHO recommended parenteral limit of 10 ng/dose to determine a corresponding upper limit on the level of residual Vero cell DNA for an oral vaccine of 10 mg. As a conservative approach, this empirically determined limit was reduced 100-fold to 100 microg. Thus, the results of this animal study, together with additional evidence in the literature, support a residual DNA safety limit of 100 microg per dose for an oral vaccine produced on a continuous cell line.

Administration, Oral↗
PubMed2006

[Arthroscopic assisted diagnosis and treatment of knee extension limitation].

OBJECTIVE: To figure out the incidence and etiology of knee extension limitation and then to find out the proper methods of arthroscopic assisted diagnosis and treatment. METHODS: We reviewed 303 cases of arthroscopic assisted operation from January to October 2003, 95 cases of which suffered from knee extension limitation before operation, including 54 male and 41female and the mean age was 36.2 years old. The direct reasons of knee extension limitation were identified by routine arthroscopic examination and operations were carried out according to results of the examination. RESULTS: Incidence of knee extension limitation in this group of patients was 31.4%. Trauma, mainly meniscus and ligament injury accounted for 67.4%, which was the most common reason of knee extension limitation. Acute or chronic arthritis like degenerative arthritis, non-specific synovitis, synovial chondromatosis, rheumatoid arthritis, pigmented villonodular synovitis, gouty arthritis and acute pyogenic arthritis formed another common reason. The follow-up period ranged from 3 to 20 months, average 13.3 months. 82 cases gained full extension immediately after operation, 9 cases gained full extension after 3 weeks rehabilitation post-operation, 4 cases did not gain full extension 1 year after operation, recurrence was observed in 4 cases. CONCLUSIONS: Arthroscopy is the best method for diagnosis of knee extension limitation at present. Satisfactory results can be expected after early arthroscopic assisted treatment.

Adolescent↗
PubMed2006

LOAD limits for ambulatory pulse pressure and double product in normotensive and hypertensive subjects.

OBJECTIVE: The aim of this study was to to determine possible daytime (awake hours) and nighttime (sleeping hours) LOAD limits for ambulatory pulse pressure (PP) and double product (DP) in hypertensive (HT) subjects and secondly to assess whether there were significant differences in the LOAD values between hypertensive (HT) and normotensive (NT) subjects. METHODS: Seventy-eight untreated essential HT (46 female, 32 male; mean age 51.9+/-1.4 years) and 115 NT (89 female, 26 male; mean age 40.8+/-1.1 years) subjects participated in this study. Ambulatory blood pressure monitoring (ABPM) devices were applied to these subjects for 48 hours. Different possible ambulatory PP LOAD limits between 40 and 55 mmHg with 5 mmHg increments and ambulatory DP LOAD limits between 6000 and 12,000 mmHg x beats/min with 1000 mmHg x beats/min increments were used. Then according to these limits, LOAD values of NT and HT subjects have been assessed for daytime, nighttime and 48 hours. RESULTS: There were significant differences between NT and HT subjects in all the values for both ambulatory PP and DP. Although mean (total, day and night mean) values of HT subjects were higher approximately by 20% than of NT subjects, LOAD values for ambulatory PP in HTs were 33%-415% higher than in NTs (p<0.001). Hypertensive subjects' mean (total, day and night mean) values of DP were by 23%-33% higher than NTs values, but LOAD values for ambulatory DP in hypertensives were approximately 43%-673% higher than in NT subjects (p<0.001). CONCLUSIONS: We showed that although there were significant differences in the 48-hour, daytime and nighttime PP and DP means between NT and HT subjects, these differences became more prominent when possible LOAD limits were used for ambulatory PP and DP, One of these possible ambulatory PP and DP LOAD limits can be used in the clinical settings if a relationship with the end-organ damage will be showed by further studies.

Adult↗
PubMed1991

Critical limits for emergency clinician notification at United States children's hospitals.

Critical results demand rapid patient evaluation, possibly followed by life-saving intervention. A national survey of children's hospitals determined the critical limits used for emergency notification of critical laboratory results. Mean low and high critical limits for children for the tests listed most frequently were as follows (millimoles per liter): glucose, 2.6 and 24.7; potassium, 2.8 and 6.4; calcium, 1.62 and 3.17; and sodium 121 and 156. For newborns, significantly different (P less than .01) critical limits were glucose, 1.8 and 18.2; and potassium, 7.8. Hematology mean critical limits for children included hemoglobin, 69 and 208 g/L; platelets, 53 and 916 x 10(9)/L; hematocrit, 0.20 and 0.62 L/L; and white blood cell counts, 2.1 and 42.9 x 10(9)/L. Critical limits for pH were 7.21 and 7.59; for PCO2, 21 and 66 mm Hg; and for PO2, 45 and 124 mm Hg. Important qualitative critical results included blasts on the blood smear and abnormal cerebrospinal fluid findings. In comparison with other medical centers, children's hospitals maintained tighter critical limits for surveillance of renal function, hemostasis dysfunction, and newborn hypokalemia. Use of these results to eliminate outliers can help reduce unnecessary statim notification and improve resource utilization for the acute diagnosis and treatment of critically ill newborns and children.

Chemistry, Clinical↗
PubMed1990

Critical limits for urgent clinician notification at US medical centers.

A national survey determined critical limits used by trauma and medical centers in the United States. Mean low and high critical limits for the most frequently listed tests were the following values: glucose, 2.6 and 26.9 mmol/L; potassium, 2.8 and 6.2 mmol/L; calcium, 1.65 and 3.22 mmol/L; sodium, 120 and 158 mmol/L; hematocrit, 0.18 and 0.61; hemoglobin, 66 and 199 g/L; platelets, 37 x 10(9)/L and 910 X 10(9)/L; and white blood cell count, 2.0 X 10(9)/L and 37.0 X 10(9)/L. The high critical limit for prothrombin time was 27 seconds. Critical limits for PCO2 were 19 and 67 mm Hg; and for pH, 7.21 and 7.59. The low critical limit for PO2 was 43 mm Hg; no high critical limit was listed. The noncritical span for free calcium was 0.80 mmol/L. Important qualitative critical results included the presence of blasts on the blood smear, a Gram's stain or culture from blood or cerebrospinal fluid with positive results, and an elevated white blood cell count in the cerebrospinal fluid. A product of 15 years of collective medical judgment, these data should help physicians improve the quality and efficiency of acute patient care.

Blood Gas Analysis↗
PubMed1990

[Limited operation of carcinoma of the lung].

A clinical study on 207 patients was performed to evaluate partial or wedge resection for lung carcinoma in our institute. Although forced vital capacity decreased 300 ml in cases with poor lung function, blood gas analysis and performance status showed no change due to limited operation. Relative non-curative cases undergoing limited operation showed a relatively good result compared to standard lobectomy, and the 5-year survival rate was 42% postoperatively, but absolute non-curative cases showed a much poorer postoperative prognosis. Reduction surgery by limited operation did not have significant effect on the survival of the patients. Limited operation for recurrent lung cancer showed good results and 5-year survival was 60% postoperatively. It was suggested that limited operation for such selected patients can be a beneficial therapeutic modality. In conclusion, limited resection is not indicated for peripheral lung cancers of more than 3 cm in diameter, poor differentiation or marked cell atypia, because of higher incidence of lymph node metastasis and early postoperative recurrence, especially in adenocarcinoma.

Aged↗
PubMed1989

Renal effects from limitation of high dietary protein in normoalbuminuric diabetic patients.

Glomerular hyperfiltration may be a risk factor for late nephropathy. It has been shown that considerable protein restriction can lower glomerular filtration rate (GFR). To elucidate the effect of moderate protein limitation in type 1 (insulin-dependent) diabetics with normoalbuminuria, eight such patients were selected for the study (age 38 +/- 7 years SD, diabetes duration 21 +/- 9 years). The patients were randomized to follow, alternately, four weeks of their usual protein intake (19% of energy) and four weeks of a limited protein intake (12% of energy). Kidney function was investigated after the two dietary periods. GFR and renal plasma flow (RPF) were measured using a constant infusion technique (125I-iothalamate/131I-hippuran), and urinary albumin excretion (UAE) by radioimmunoassay. It was found that the limited protein diet reduced GFR from 146 +/- 23 to 132 +/- 24 ml/min/1.73 m2 (2P less than 0.005). A tendency towards a fall in RPF was seen (549 +/- 128 vs. 503 +/- 125 ml/min; 2P = 0.06), while total renal resistance rose from 0.17 +/- 0.03 to 0.20 +/- 0.05 mm Hg/ml/min (2P = 0.05). No significant changes in filtration fraction, UAE and blood pressure were seen. HbA1c, fructosamine, insulin dose and body weight were unchanged during the two diets; also serum protein, albumin, phosphate and calcium remained unaltered. Serum urea was significantly reduced on the limited protein intake. Patients were generally pleased with the limited protein diet. Thus, limitation of the often high protein intake in diabetics might be valuable and realistic. The long-term renal protective effect remains to be investigated.

Adult↗
PubMedDate not supplied

[A limited turbidostat yeast culture under heat shock conditions].

A response of limited turbidostat S. cerevisiae 14 culture on rapid increase in temperature from optimal 30 degrees to supraoptimal 37.5 degrees C. The temporal thermotolerance was absent in glucose and phosphate-limited cultures. Limitation of nitrogen, Mg, betaalanine, biotin, and, to a certain extent, potassium did not decrease the thermotolerance. The pattern of changes in age composition and specific optical density was found to be similar in limited and unlimited cultures. The glucose and phosphate expenditures at 37.5 degrees C were estimated. The response to heat shock was found to depend on the nature of the limiting factor and the extent of limiting.

Culture Media↗
PubMed1989

[Ultrastructural studies on invasion of inner limiting membrane by malignant tumor cells].

In order to observe the process of invasion, retina of rat was used as a model to substitute the inner limiting membrane of retina for the basement membrane. Retina invaded by esophageal carcinoma cells and B16 melanoma cells upon the inner limiting membrane was studied by scanning and transmission electron microscopy. The results showed that the inner limiting membrane was destroyed by the two kinds of tumor cells mentioned above. The process of destruction was followed by a series of transformation in the inner limiting membrane, i.e. folding, swelling, thickening, and granulation. The inner limiting membrane was dissolved focally as a result of transformation, and then tumor cells invaded the retina through these dissolved regions. It seems that, like a barrier, the inner limiting membrane plays a similar role as the basement membrane.

Aged↗
PubMed1989

Effects of the 65-mph speed limit on rural interstate fatalities in New Mexico.

As a result of federal legislation passed in April 1987, New Mexico was the first state to resume a 65-mph speed limit on rural Interstate highways. We compared the rates of fatal crashes before and after the speed limit change. The rate of fatal crashes in the 1 year after the speed limit was increased was 2.9 per 100 million vehicle-miles traveled, compared with a predicted rate of 1.5 per 100 million vehicle-miles based on the trend of the 5 previous years. When fatal crashes that occurred after the speed limit change were compared with fatal crashes in the 5 previous years, there was no difference in the mean age and sex of the at-fault drivers, mean age and sex of the victims, seat belt use by the victims, or alcohol involvement of the crashes. The increase in fatal crashes can be attributed to an increase in fatal single-vehicle crashes. Vehicles on rural Interstates are traveling at greater rates of speed and a larger proportion of vehicles are exceeding the 65-mph speed limit. The benefits associated with the 65-mph speed limit should be weighed against the increased loss of lives.

Accidents, Traffic↗
PubMed1986

Carbamazepine and 10,11-epoxycarbamazepine produce use- and voltage-dependent limitation of rapidly firing action potentials of mouse central neurons in cell culture.

Effects of the anticonvulsant, carbamazepine (CBZ), on mouse central neurons in cell culture were examined using intracellular recording techniques. Spinal cord and cortical neurons demonstrated sustained repetitive firing (SRF) of action potentials (APs) at high frequency in response to depolarizing current pulses. Hippocampal neurons fired rapidly only in the pressure of the calcium channel blocker verapamil (1 microM). Concentrations of CBZ equivalent to therapeutic anticonvulsant levels in cerebrospinal fluid (greater than 4.2 microM) limited firing to a few action potentials in all three cell types in parallel with use-dependent reduction of AP maximal rate of rise (Vmax). Resting membrane properties and postsynaptic responses to ionophoretically applied gamma-aminobutyric acid and glutamate were unaffected. The CBZ metabolite, 10,11-epoxycarbamazepine, limited SRF at a concentration (4 microM) encountered at therapeutic CBZ levels. Another major CBZ metabolite, the 10,11-diol, limited SRF only at concentrations greater than those encountered with therapeutic serum CBZ levels. In control medium, APs could be evoked at a maximal rate of 450 Hz while in CBZ (10.6 microM) AP frequency was limited to 100 to 200 Hz. Limitation of SRF was voltage-dependent and could be partially reversed, or prevented, by membrane hyperpolarization. In addition, recovery of Vmax of sodium-dependent action potentials from inactivation was slowed, suggesting an effect on voltage-dependent sodium channels. CBZ and phenytoin effects of SRF were similar. We suggest that limitation of sustained high frequency repetitive firing may be a significant anticonvulsant action of carbamazepine. The 10,11-epoxy derivative of CBZ, but not the 10,11-diol, may contribute to anticonvulsant efficacy by the same mechanism.

Action Potentials↗
PubMedDate not supplied

Limited licensing: why is the ARRT involved? Part II.

Due primarily to economic factors, the concept of the limited scope operator would exist regardless of any organization's position on the wisdom of the concept. Most states that have passed laws as encouraged by federal legislation have been reluctant to legislate people out of existing jobs and have, therefore, incorporated limited categories of practice into their laws. This further assures the survival of the concept of the limited scope of practice. Acknowledging the existence of the position and working to establish reasonable training and competence assessment procedures is in the best interest of the public as well as of the radiography profession. The ARRT is therefore committed to developing examinations for use by states licensing the limited scope of practice operator. The examinations are based upon the philosophy that those persons having a scope of practice that is limited to radiography of the chest or extremities must be as knowledgeable in those particular areas as is the general staff radiographer at entry level as defined by the ARRT Job Analysis Project. Examinations developed using this philosophy will enable states to restrict limited licensing to only those persons having met realistically high standards that are consistent across the country.

Licensure↗
PubMed1985

Limited joint mobility in insulin-dependent diabetes: relationship to retinopathy, peripheral nerve function and HLA status.

Eighty-eight (43 per cent) of 204 patients with insulin-dependent diabetes had limited joint mobility affecting mainly the small joints of the hands. The presence of limited joint mobility correlated with duration of diabetes and with the presence of retinopathy. Patients with longstanding diabetes were approximately 2.5 times more likely to have proliferative retinopathy if limited joint mobility was present than if it was absent, although the risk for non-proliferative or background retinopathy was not increased. In patients with longstanding diabetes and limited joint mobility nerve conduction velocity and vibration perception threshold were significantly reduced compared with patients having similar duration of diabetes but normal joints. The association between insulin-dependent diabetes and HLA-DR3 and HLA-DR4 was confirmed, but there was no difference, between patients with and without limited joint mobility, in the frequency of the various HLA types. Limitation of joint mobility appears to be another "chronic complication' of diabetes, developing in parallel with retinopathy and deteriorating peripheral nerve function, and possibly of similar aetiology.

Adult↗
PubMedDate not supplied

[Comparison of casein utilization limited by different amino acids].

Experiments of Wistar rats were made to compare the utilization of proteins limited by sulfur-containing amino acids or isoleucine. The score of the limiting amino acid of the proteins under study was identical (0.65). The diets included 2, 5, 10, 15, 20, 25, 30, 40 and 50 g protein per 100 g diet. Depending on the protein content in the diet, the following values of net protein utilization (NPU) were obtained for protein limited by sulfur-containing amino acids: 0.680, 0.647, 0.616, 0.600, 0.562, 0.460, 0.315, 0.240, 0.210. Meanwhile, the values for protein limited by isoleucine were 0.700, 0.697, 0.600, 0.560, 0.524, 0.450, 0.340, 0.260, 0.200. Despite insignificant differences in feed consumption and weight gains in the animals, the above cited values of the NPU did not differ essentially in terms of test protein concentration under comparison. The data obtained indicate that the biological value of proteins limited by sulfur-containing amino acids does not differ from that of proteins limited by isoleucine.

Amino Acids, Sulfur↗
PubMed1983

Functional limitation in aortic valve disease: superiority of bicycle test to symptom-rated appraisal?

The overall functional capacity in aortic valve disease was evaluated using the New York Heart Association criteria and symptom-limited bicycle ergometry in 80 patients who underwent cardiac catheterization. The correlations between exercise performance and resting cardiac haemodynamics and clinical class were poor. Similar exercise tolerance appeared to be associated with comparable resting left ventricular (LV) performance in each haemodynamic subgroup. Limitation in exercise tolerance in aortic stenosis (n = 25), as defined by peak work-load achieved and work-pulse index, together with an inability to raise systolic blood pressure during exercise, appeared to be associated not only with a more significant reduction in LV systolic pump function and compliance but also with greater LV dilatation. A lack of correlation between exercise performance and resting LV function was seen in patients with aortic regurgitation (n = 35); and, to large extent, in those with combined lesion (n = 20). The severity of the valvular lesion was not indicated by functional limitation in any of the subgroups, although greater systolic blood pressure during exercise appeared to reflect more significant valvular leakage in the combined lesion group. It is concluded that objective tests of exercise tolerance are to be preferred in monitoring the course of the disease and the therapy provided. Aortic regurgitation appears to cause as great a limitation in exercise tolerance as does aortic stenosis alone, but may not be associated with greater deterioration in LV function at a similar level of functional limitation. Pressure overload to the LV may explain the ability of impaired LV function to reflect the limitation in exercise tolerance in cases of aortic stenosis.

Adult↗